Leburg ignition replacement

[Kamcoman77]

Sounds like you can screw a thin aluminum disc with pickup bolt/nut to the back of the mag adapter and make a sensor mounting plate that you can bolt to the case. My sensor plate mounts the Start sensor at 2 degrees after top dead center so a kickback is nearly impossible. The Run sensor is at 28 degrees before top dead center since my research says 28° BTDC is the best setting for the 1/2 VW. Show us a photo of the back of the engine with the mag removed.

[Mark Kramer]

Will do. However my prop is due back from Frank today and I’m dying to run it and check rpms and thrust at WOT. Provided I’m happy with those numbers, I’ll pull the mag and we can brainstorm a set up. Thanks for all the patience  with my slowness to understand things .

[Kamcoman77]

Mark, I like the idea of the two switches and two 4L80E magnetic pickup sensors (bolt triggered) with no diodes, no programming, no resistors, etc. This seems to be the system with the simplest setup. Once you have a bracket that can hold the pickup sensors in the correct position, running the wiring is very straightforward. I have run my two-pickup test setup firing a Honda motorcycle coil and also the Buick V6 coil. Both gave very hot sparks and drew less than 1/2 amp at 1,000 rpm and 1.1 amp at 3,000 rpm. I did not run my test at a higher rpm. When I get my 1/2 VW built and running, I will have higher rpm data. With my homemade battery pack of 6.8 amp hour capacity, I will have more than 4-hours of run time at full throttle. I will also have an air driven charging system that I can switch on any time during flight to bring the battery back to full charge, if needed.

[Mark Kramer]

I definitely like simple and easy. My next hurdle is to master welding aluminum so I can make the bracket. I used a tig welder for the fuselage which was super easy to get beautiful welds. Aluminum is another story. I think I need a larger tip and a little knowledge on how to set up the welder. I wonder what diameter the aluminum disc should be? I’m thinking 4.5 in with the bolt at 4in. Plus if you put a 1/4 in. bolt on one side of the wheel, seems like you would have to balance it somehow. Oh, one other thing, Wayne said all modules need a heat sink. Does that mean mounting the HEI on a finned aluminum kind of thing? I wish I had better knowledge of the dependability and longevity of this system. If I lived and flew somewhere with lots of empty fields around the airport, I wouldn’t worry so much. Here in Maine, large fields don’t exist, and an engine out away from the runway would be very bad. I fantasize about living somewhere warm with my own grass runway surrounded by sod farms.

[Kamcoman77]

The module does need to be mounted on some type of heat sink. If you look at my bench test setup in Post #13, you will see the module is mounted on a 1/4" thick aluminum plate. Although I have not run the system for over 10 minutes at any one time, the module never even got warm, much less the plate. Your aluminum disc diameter needs to be large enough so the trigger bolt is in the same arc as the sensors. The sensors need to be mounted in such a way that they can be 28° or 30° apart. I had to use a 4-1/2" circle for my sensors because the rear of the sensors would not allow closer positioning for a smaller circle. For balance you could use two bolts (same size), installed in your disc 180° apart, with the long end of the bolts reversed so only one long end passes the sensors.

[Mark Kramer]

Got it. Can’t wait to start fabricating parts, helping my stepson on his house for a few days now. Like it or not there is life beyond airplanes. I talked to a welder guy and bought some new tip parts for the tig. Hoping to make a nice bolt on mag replacement set up for the back of the engine.

[Pietflyr2]

Kamcoman77.
I've followed your posts on this subject and have been working on a system for my installation. A question. I've been having trouble coming up with terminal "blades" to fit inside the coil pack. Do you remember what you may have used on your set-up? Reference to reply #13 photo of your set-up.

[Kamcoman77]

Lots of stuff going on in post #13, but I think you mean the connectors that fit into the base of the Buick coil. If so, I used standard male blade connectors that are usually available at any auto parts store. I just crimped them onto 16ga stranded wire with male connectors crimped on the other end and run to the module. I've been test running the engine with two 4L80E pickup sensors instead of the Ford ABS and one 4L80E. The 4L80E's put out a little hotter spark.

[Pietflyr2]

Thank you sir. Right after I wrote this I found a site that showed a way to disable the computer in a Cavalier ignition module and use the pins for direct hookup to the crank sensors. I appreciate your help in this project.